Ink jet recording method for printing pigment

ABSTRACT

There is provided an ink jet recording method for printing a pigment in which a pigment printing ink composition including at least pigment as a colorant is discharged from a nozzle opening as an ink droplet having an amount of the ink of the ink droplet of 9 ng or less with an average discharging speed V of 5 m/s or greater at a distance in the range of 0.5 mm to 1.0 mm in the direction from the nozzle opening to cloth, and whereby the pigment printing ink composition is adhered to the cloth.

BACKGROUND

1. Technical Field

The present invention relates to an ink jet recording method forprinting pigment.

2. Related Art

In the related art, various methods have been used as a recording methodfor forming an image based on image data signals on a recording mediumsuch as paper. Among these, in an ink jet system, it is possible toefficiently use an ink composition and running cost is low since the inkjet system is not expensive and the ink composition is discharged ontoonly the necessary image portion to directly form an image on therecording medium. Furthermore, the ink jet system makes little noise andtherefore, it is excellent as a recording method.

In recent years, applying an ink jet recording system to dyeing of acloth (textile printing) has been studied. For example, an ink jet inkcomposition is disclosed in which in order to provide a durability and acolor fastness against washing to a textile which is ink jet printed, anaqueous vehicle, a colorant and a crosslinked polyurethane dispersantare included (for example, refer to JP-T-2007-522285).

Furthermore, an ink set for ink jet printing is disclosed which isconfigured with respective ink jet printing inks of yellow, magenta,cyan or blue and black containing at least a disperse dye, a dispersant,water and a water-soluble organic solvent in order to provide an ink setfor ink jet printing by which a stable image with respect to a change inthe drying conditions of a printed cloth is obtained (for example, referto JP-A-2005-263837).

Furthermore, a method is disclosed in which printing is performed byapplying ink of at least two colors of orange and red on a cloth usingan ink jet system in order to provide an ink jet printing method inwhich a printed matter having a particularly wide color reproductionrange from orange to scarlet can be obtained, and a stable image can beobtained even when dyeing treatment conditions by heating vary to someextent when an ink jet printing is performed on a cloth configured withmainly fibers capable of being dyed with a disperse dye (for example,refer to Japanese Patent No. 2952133).

In addition, an ink jet printing method is disclosed in which printingis performed such that a discharging speed of ink droplets from a nozzleand the mass of the ink droplets satisfy a predetermined relation, in amethod in which ink droplets are continuously discharged from the nozzleby applying pressure to the ink whereby printing is performed on a clothin order to provide an ink jet printing method in which the scatteringof ink is suppressed and a high quality image without contamination canbe printed in the case of printing on a cloth in a continuous ink jetsystem such as a charge amount deflection type ink jet (for example,refer to JP-A-7-119048).

However, in the above-described related art, there are problems in thatif reducing an amount of the ink of the ink droplet in order to obtainan image with a higher resolution and a higher image quality, or tofurther increase a drying speed, ink droplets are likely to remain onfuzz (hereinafter, simply referred to as “fluff”) of the cloth surface,and at the time of heat press, fluff collapses to contact the baseportion of the cloth, the ink droplets remaining in the fluff adhere tothe base portion of the cloth and contaminate the cloth, and as aresult, cohesion unevenness and bleeding occur. In addition, there isalso a problem in that in the case of a dye printing ink composition,ink is unlikely to adhere to the base portion of the cloth even in thecase where the fluff collapses since the coloring material of the inkattached to the surface of the fluff is likely to penetrate into theinside of the fluff. However, in the case of a pigment printing inkcomposition (hereinafter, simply referred to as “ink composition”), inkremaining on the surface of the fluff at the time when the fluffcollapses is likely to attach to the base portion of the cloth tocontaminate the cloth since the pigment attached to the surface of thefluff is unlikely to penetrate into the inside of the fluff.

In addition, there is also a problem in that in the case where inkdroplets do not reach the base portion of the cloth since the inkdroplets are attached to the fluff, a concealing property of an imagebecomes poor.

SUMMARY

An advantage of some aspects of the invention is to provide an ink jetrecording method for printing a pigment in which contamination of acloth is suppressed and a concealing property and a drying speed of theobtained image are excellent.

The present inventors performed thorough studies. In ink jet printing ofa pigment printing ink composition on the cloth, in the case of printingafter setting the amount of the ink per one ink droplet to be small,there are advantages in that an image with a high-resolution and a highimage quality can be obtained, or the drying speed can be increased. Incontrast, ink droplets are unlikely to reach the base portion of thecloth since the ink droplets adhere to the fluff compared with a casewhere the amount of the ink per one ink droplet is large, and there is aproblem in that image quality is likely deteriorated by collapse of thefluff at the time of a heat press after ink is applied. The inventorshave found that by setting the amount of the ink droplets to apredetermined amount and setting the speed to a predetermined speed, itis possible to suppress adhesion of the ink droplets to the fluff and tomake ink droplets reach the base portion of the cloth and the problemscan be solved, and have completed the invention.

That is, the invention is as follows.

[1] An ink jet recording method for printing a pigment, in which apigment printing ink composition including at least pigment as acolorant is discharged from a nozzle opening as an ink droplet having anamount of an ink of 9 ng or less with an average discharging speed V of5 m/s or greater at a distance in the range of 0.5 mm to 1.0 mm in thedirection from the nozzle opening to cloth, and the pigment printing inkcomposition adheres to the cloth.

[2] The ink jet recording method for printing a pigment described in[1], in which the distance between the nozzle opening and the cloth isin the range of 2.0 mm to 5.0 mm.

[3] The ink jet recording method for printing a pigment described in [1]or [2], in which the amount of the ink of the ink droplet is 5.9 ng, andthe average discharging speed V is in the range of 5 m/s to 10 m/s.

[4] The ink jet recording method for printing a pigment described in anyone of [1] to [3], in which the solid content of the pigment printingink composition is 8% by mass or greater.

[5] The ink jet recording method for printing a pigment described in anyone of [1] to [4], in which the pigment printing ink compositionincludes a pigment, and a resin dispersion.

[6] The ink jet recording method for printing a pigment described in anyone of [1] to [5], in which the cloth includes cotton or a cotton blend.

[7] The ink jet recording method for printing a pigment described in anyone of [1] to [6], in which after the pigment printing ink compositionis adhered to the cloth, the cloth to which the pigment printing inkcomposition is adhered is heat-treated by a heat press.

[8] The ink jet recording method for printing a pigment described in[7], in which a heating temperature is 150° C. or higher in the heattreatment.

[9] The ink jet recording method for printing a pigment described in anyone of [1] to [8], in which the amount of the pigment printing inkcomposition adhering to the cloth is in the range of 10 mg/inch² to 70mg/inch².

[10] The ink jet recording method for printing a pigment described inany one of [1] to [9], in which a dot formation density of the pigmentprinting ink composition on the cloth is 720 dpi or greater×720 dpi orgreater.

[11] The ink jet recording method for printing a pigment described inany one of [1] to [10], in which the pigment printing ink composition isany one of a color ink including at least color pigment as a pigment anda black ink including at least carbon black pigment as a pigment.

[12] An ink jet recording apparatus, in which recording is performed bythe ink jet recording method for printing a pigment described in any oneof [1] to [11].

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a schematic diagram for showing a progress in which inkdroplets discharged from a nozzle opening are adhered to a cloth.

FIG. 2 is a view showing an example of a waveform of a driving signalfor driving a head.

FIG. 3 is an example of a block diagram of an entire constitution of an(entire) ink jet recording apparatus.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, embodiments for carrying out the invention (hereinafter,referred to as “the embodiment”) will be described in detail. Further,the invention is not limited thereto, and various modifications arepossible without departing from the gist of the invention.

1. Ink Jet Recording Method for Printing Pigment

In the ink jet recording method for printing a pigment of theembodiment, a pigment printing ink composition including at leastpigment as a colorant is discharged from a nozzle opening as an inkdroplet having an amount of the ink of the ink droplet of 9 ng or less,with an average discharging speed V of 5 m/s or greater at a distance inthe range of 0.5 mm to 1.0 mm in the direction from the nozzle openingto cloth, and whereby the pigment printing ink composition is adhered tothe cloth.

1. Discharging Method

In FIG. 1, a progress in which ink droplets discharged from the nozzleopening are adhered to cloth is shown. It is desirable that an inkdroplet 2 discharged from a nozzle opening 1 reach the base portion 3 ofthe cloth without adhering to fluff 4 (ink droplet 2 a). However, in therelated art, there is a case where the ink droplet 2 does not reach thebase portion 3 of the cloth since the ink droplet 2 is adhered to thesurface of the fluff 4 (ink droplet 2 b), or there is a case where theink droplet 2 b adhering to the surface of the fluff 4 is adhered to thebase portion 3 of the cloth at the time when the fluff 4 collapses tocontaminate the cloth (ink droplet 2 c). The ink jet recording methodfor printing a pigment of the embodiment has a configuration in whichink droplet 2 discharged from the nozzle opening 1 reaches the baseportion 3 of the cloth without adhering to the surface of the fluff 4.The configuration is as follows.

The amount of an ink droplet of the pigment printing ink compositiondischarged from the nozzle opening is 9 ng or less, preferably in therange of 1 ng to 9 ng and more preferably in the range of 5 ng to 9 ng.When the amount of the ink is in the above range, the image with highresolution with high drying speed and excellent discharging stability isobtained. The amount of the ink droplet of the pigment printing inkcomposition can be controlled by a discharging mechanism describedlater.

The average discharging speed V of the ink droplet of the pigmentprinting ink composition at a distance in the range of 0.5 mm to 1.0 mmin the direction of the cloth from the nozzle opening is preferably 5m/s or greater, more preferably in the range of 5 m/s to 15 m/s, andstill more preferably in the range of 5 m/s to 10 m/s. When the averagedischarging speed V is in the above range, contamination of a cloth isinhibited and the discharging stability is excellent. The averagedischarging speed V can be controlled by a discharging mechanismdescribed later. Moreover, as shown in FIG. 1, images of the ink droplet2 are captured with a camera or a video camera from a side of the nozzlesurface until the ink droplet 2 discharged from the nozzle opening 1passes through a distance in the range of 0.5 mm to 1.0 mm, the timewhen the ink droplet 2 passes through the distance in the range of 0.5mm to 1.0 mm in the direction of the cloth from the nozzle opening 1 ismeasured, and the average discharging speed V can be determined bycalculating from the measured values.

In addition, the amount of the ink of the ink droplet is preferably inthe range of 5 ng to 9 ng and the average discharging speed V ispreferably in the range of 5 m/s to 10 m/s. There is a possibility thatthe discharging speed at the time point at which the ink droplet landson a cloth is slower than at the time of discharging due to airresistance, and at least, when the amount of the ink of the ink dropletand the average discharging speed are in the ranges, the contaminationof the cloth can be inhibited.

The distance between the nozzle opening and the cloth is preferably inthe range of 0.5 mm to 1.0 mm, more preferably in the range of 2.0 mm to5.0 mm, still more preferably in the range of 2.0 mm to 4.0 mm, andparticularly preferably in the range of 2.5 mm to 4.0 mm. When thedistance between the nozzle opening and the cloth is in the above range,contact with the nozzle surface tends to be suppressed and thecontamination of a cloth tends to also be inhibited even in a case wherecloth which absorbs the ink composition during printing expands. Inaddition, when the distance between the nozzle opening and the cloth isin the above-described range or less, it is to possible to reduce mistsince a width of deviation from the target landing position of the inkdroplet is reduced, and disturbance does not occur in the image and theink droplet is likely to reach the cloth.

Here, “distance between the nozzle opening and the cloth” is a distancebefore recording is performed, and as shown in FIG. 1, it is a distancebetween the surface of the base portion 3 of the cloth (cloth from whichthe fluff 4 is removed) and the nozzle opening 1. On the other hand,even in the case where the cloth expands with respect to the nozzlesurface due to printing in the case where the adhered ink amount isparticularly large in the printing, a maximum expansion amount is about2 mm.

Discharging Mechanism

An ink jet recording apparatus moves the head along the main scanningdirection and discharges ink droplets from the nozzle openings of thehead in conjunction with the movement, thereby recording an image on arecording medium. For example, the discharging of the ink droplets isperformed by inflating and deflating a pressure generating chamber whichcommunicates with the nozzle openings.

For example, the inflating and deflating of the pressure generatingchamber is performed by using the deformation of a piezoelectrictransducer. In such a head, the piezoelectric transducer is deformeddepending on the driving pulse to be supplied, and by this, the volumeof the pressure chamber changes, and a pressure change is generated inthe ink composition in the pressure chamber by the volume change,whereby ink droplets are discharged from the nozzle openings.

In such an ink jet recording apparatus, a driving signal which is formedby connecting a plurality of driving pulses in series is generated. Onthe other hand, print data including gradation information istransmitted to the head. Then, only the required driving pulse isselected from the driving signal and the selected driving pulse issupplied to the piezoelectric transducer on the basis of the transmittedprint data. Thus, the amount of the ink droplets discharged from thenozzle openings changes depending on the gradation information.

More specifically, for example, in the ink jet recording apparatus inwhich the four gradation formed of non-recording print data, small dotprint data, medium dot print data and large dot print data are set, theink droplets having the different amounts of the ink are dischargeddepending on each gradation.

In order to realize the above-described arbitrary gradation recording,for example, a driving signal as shown in FIG. 2 can be used. As shownin FIG. 2, a driving signal A connects a potential raising waveform RWwhich is arranged in the period T1, a first pulse waveform PW1 which isarranged in the period T2, a second pulse waveform PW2 which is arrangedin the period T3, a third pulse waveform PW3 which is arranged in theperiod 14 and a potential lowering waveform FW which is arranged in theperiod T5 in series, and it is a pulse-train waveform signal which isrepeatedly generated with a recording period TA.

Potential raising waveform RW is waveform which linearly raises apotential with a gradient θR from a base potential VB to a first drivingpotential VM1. The base potential VB is a ground potential. Pulsewaveforms PW1, PW2 and PW3 have discharging elements P11, P21 and P31which lower the potential from driving potentials VM1, VM2 and VM3 to abase potential VB with gradients θ11, θ21 and θ31, holding elements P12,P22 and P32 which maintain the base potential VB for a short period oftime, charging elements P13, P23 and P33 which raise the potential fromthe base potential VB to the highest potentials VH1, VH2 and VH3 withgradients θ12, θ22 and θ32 in a short period of time, holding elementsP14, P24 and P34 which maintain the highest potential, and dischargingelements P15, P25 and P35 which lower the potential from the maximumpotentials VH1, VH2 and VH3 to potentials VM2, VM3 and VM4 withgradients θ13, θ23 and θ33.

These pulse waveforms PW1, PW2 and PW3 are respectively signals capableof independently discharging ink droplets. When these respective pulsewaveforms are supplied to the piezoelectric transducer, ink droplets ofthe amount capable of forming small dots are discharged from the nozzleopenings.

In this case, by increasing and decreasing the number of the drivingpulses supplied to the piezoelectric transducer, gradation control canbe performed. For example, small dots can be recorded by supplying onedriving pulse, middle dots can be recorded by supplying two drivingpulses, and large dots can be recorded by supplying three drivingpulses.

Here, the middle potential VM shown in FIG. 2 is referred to as a biasvoltage. The potential of the piezoelectric transducer is maintained inany state among the lowest potential VL, the highest potential VH andthe middle potential VM. By keeping such an intermediate state as thestate at the time of starting the driving, a volume change can begenerated on the expansion side and on the contraction side.

By adjusting the potential difference of the charging elements P13, 23and 33, the amount of the ink per one ink droplet can be adjusted.Moreover, one recording cycle corresponds to the recording resolution,and one pixel is recorded in one recording cycle. In addition, bychanging the gradients θ12, θ22 and θ32 of the charging elements P13,P23 and P33 of the driving pulses PW1, PW2 and PW3, the dischargingspeed can be adjusted.

Furthermore, for example, when six driving pulses are applied to thepiezoelectric element in one recording cycle, six ink droplets can bedischarged. In this case, when the driving frequency of one recordingcycle is set to 7.2 kHz, discharging frequency of this case becomes 43.2kHz. In addition, in the case where the driving frequency of onerecording cycle is set to 7.2 kHz, when there is an intention to set thedischarging frequency to 21.6 kHz, an ink composition may be dischargedby applying only three driving pulses to every other out of six drivingpulses PAPS to the piezoelectric element. Similarly, when there is anintention to set the discharging frequency to 14.4 kHz, an inkcomposition may be discharged by applying only two pulses to every twoout of six driving pulses to the piezoelectric element, whereby it ispossible to control the discharging frequency.

Printer

FIG. 3 is an example of a block diagram showing an entire constitutionof the (entire) ink jet recording apparatus which performs recording bythe ink jet recording method of the embodiment. An ink jet printer 10has a transport unit 20, a carriage unit 30, a head unit 40, a sensorgroup 50 and a controller 60. The ink jet printer 10 which receives aprint signal PRT from a computer 110 having a display device 120controls respective units by the controller 60 and performs recording onthe recording medium. The controller 60 has a unit control circuit 64, aCPU 62, a memory 63 and an interface portion 61. The head unit 40 hasthe head and the discharging mechanism, and the discharging speed anddischarging frequency at the time of recording, the amount of the inkand the like are adjusted by control of the head unit 40 by thecontroller 60. A carriage unit moves the head along the main scanningdirection. A transport unit transports a recording medium in thetransport direction.

2. Adhesion and Heat Treatment

In the ink jet recording method of the embodiment, an image is formed bya discharged pigment printing ink composition adhering to a cloth. Afterthe pigment printing ink composition is adhered to the cloth, a dryingstep in which the cloth to which the pigment printing ink composition isadhered is heat-treated by a heat press is preferably performed. By theheat treatment, it is possible to fuse a resin (polymer) capable ofbeing included in an ink composition on the surface of the cloth, and itis possible for water to evaporate. Thus, friction resistance of theobtained image tends to be more improved further. Moreover, in thiscase, contamination by the fluff is likely generated. However, in themethod according to the embodiment, the contamination of the cloth canbe suppressed since ink droplets reach the base portion of the cloth,and the ink droplets do not remain in the fluff.

As the heat treatments, which are not particularly limited, a heat pressmethod, a normal pressure steam method, a high pressure steam method,and a thermofix method are exemplified. In addition, as the heat sourceof heating, which is not particularly limited, an infrared light (lamp)is exemplified. Further, the temperature at the time of heat treatmentmay be a temperature at which a resin (polymer) capable of beingincluded in an ink composition can be fused and water can evaporate, ispreferably 150° C. or higher, and is more preferably in the range ofabout 150° C. to 200° C. When the temperature at the time of heattreatment is in the above range, more excellent friction resistancetends to be obtained.

After the heating step, the cloth may be washed and dried. At this time,a soaping treatment, that is, a treatment of washing off a non-fixedpigment with a heated soap liquid may be performed as necessary.

In this manner, it is possible to obtain a recorded material in which animage derived from the ink composition of the embodiment is formed onthe cloth. The recorded material has an excellent coloring propertysince generation of cracks, irregularities and dirt can be prevented,and also has excellent friction resistance since the fixation(adhesiveness) of an ink composition is excellent.

Adhered Amount of the Ink Composition

In addition, the lower limit of the adhered amount of the pigmentprinting ink composition with respect to the cloth is preferably 10mg/inch² or greater and more preferably 20 mg/inch² or greater. Theupper limit is preferable 100 mg/inch² or less, more preferably 70mg/inch² or less, and still more preferably 50 mg/inch². When theadhered amount of the ink composition is in the above range, an imagehaving a desired color by a color ink is likely formed, and the dryingspeed can also be improved.

Dot Formation Density

“Dot formation density” refers to a formation density of each inkdroplet which is discharged on a recording medium, and is represented bythe horizontal direction (main scanning direction, a width direction) ofa recording medium×the vertical direction of a recording medium(sub-scanning direction, transport direction) (respective dpi). On theother hand, “recording resolution” refers to the density of the minimumrecording unit (pixel) capable of controlling the gradation on the basisof the print data. In some cases, the dot formation density is the sameas the recording resolution. However, it is not necessarily the same.The dot formation density of the pigment printing ink composition on acloth is preferably 600 dpi or greater, more preferably 1200 dpi orgreater, and still more preferably 1400 dpi or greater in both thedirections. In the ink jet recording method for printing a pigment ofthe embodiment, the image can be printed at such a high dot formationdensity.

2. Cloth

Next, the cloth used in the embodiment will be described. As the cloth,which is not particularly limited, natural fibers or synthetic fiberssuch as silk, cotton, wool, nylon, polyester and rayon are exemplified.Among these, the cloth may include cotton or a cotton blend from theviewpoint of a sense of touch. In addition, in the case of cotton orcotton blended cloth, there is a tendency that ink droplets are unlikelyto reach the cloth surface since the fluff is erect, and thus, the inkdroplets are trapped thereby. For this reason, in the case of cotton orcotton blended cloth, the need to solve the problem by applying theinvention is particularly great. The cotton blended cloth preferablyincludes cotton of 10% by mass or greater to less than 100% by mass,more preferably includes cotton of 30% by mass or greater to less than100% by mass, and still more preferably includes cotton of 52% by massor greater to less than 100% by mass. When the ratio of the cottonblended cloth is in the above range, the sense of touch tends to befurther improved. In addition, as other fibers which are blended, whichare not particularly limited, polyester and the like can be used.

3. Ink Jet Recording Method for Printing Pigment

The ink composition used in the embodiment is a pigment printing inkcomposition, and an aqueous pigment printing ink composition and anoil-based pigment can also be used. In the case where the ink is thepigment printing ink composition, the ink remaining on the surface ofthe fluff at the time when the fluff collapses is likely to be attachedto the base portion of the cloth to contaminate the cloth since thepigment attached to the surface of the fluff is unlikely to penetrateinto the inside of the fluff. In contrast, in the case where the inkcomposition is a dye printing ink composition, since the coloringmaterial of ink composition is likely to penetrate into the inside ofthe fluff, the ink is unlikely to adhere to the base portion of thecloth even when the fluff collapses. On the other hand, when using thedye printing ink composition, a chemical treatment or a steam heattreatment is needed for fixing, and the dye needs to change according tothe type of textures. However, when using the pigment printing inkcomposition, there are advantages in that only a post-treatment such asa heat treatment may be performed since the pigment is fixed by a fixingresin, and printing can be simply performed regardless of the type oftextures. The contamination of the cloth can be suppressed while theadvantage of the pigment printing ink composition is taken.

The pigment printing ink composition, which is not particularly limited,preferably includes a pigment and a resin emulsion, and more preferablyfurther includes a water-soluble solvent. The fixation of a pigmenttends to be further improved. In addition, when the ink compositionincludes the pigment and the resin emulsion, there is a tendency thatthe ink is more unlikely to penetrate into the fluff, and in such acase, the invention is particularly useful. Furthermore, a water-solubleresin can also be used as the resin emulsion, and even in this case,there is a tendency that the ink is more unlikely to penetrate into thefluff, and therefore, the invention is particularly useful. Hereinafter,the additives (components) which are included or can be included in theink composition will be described in detail.

In the pigment printing ink composition, the upper limit of the solidcontent is preferably 5% by mass or greater, more preferably 8% by massor greater, and still more preferably 10% by mass or greater. The lowerlimit of the solid content is preferably 25% by mass or less, morepreferably 20% by mass or less, and still more preferably 15% by mass orless. When the solid content is in the above range, the concealingproperty, the friction resistance, storage stability, and thedischarging stability of the obtained image tend to be improved. Thesolid content is included in the ink and is not volatilized when the inkis dried. The solid content is components which remain on a recordingmedium as a solid at room temperature over a long period of time afterthe ink is dried, and is components excluding water and organicsolvents. Mainly, a coloring material, a resin and the like correspondto the solid content.

The pigment printing ink composition preferably includes the pigment of0.5% by mass to 15% by mass, more preferably 1% by mass to 10% by mass,and still more preferably 1% by mass to 5% by mass. When the content ofthe pigment is in the above range, there is a tendency that the colordevelopment and the concealing property of an image are likely obtained.

1. Coloring Material

In the case where the adhered amount of the ink to the cloth as thecolor ink is small, there is a tendency that contamination is likely tobe conspicuous if the fluff collapses. In addition, in the case of notapplying a pretreatment liquid to the cloth before printing, there is atendency that contamination is likely to occur by collapsing of thefluff when a heat press was performed. Therefore, the invention isparticularly useful in the case where a pretreatment is not used, or inthe case where the adhered amount of the ink is small (the case where animage is formed on white cloth by color inks and the like). However, itis not particularly limited to the above cases.

In the pigment printing ink composition used in the embodiment, coloringmaterials exemplified below can be used. As the carbon blacks, which arenot particularly limited, furnace black, lamp black, acetylene black andchannel black (C. I. Pigment Black 7) can be exemplified. Furthermore,as commercially available carbon blacks, No. 2300, 900, MCF88, No. 20B,No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100, No. 2200B(hereinbefore, product names, all manufactured by Mitsubishi ChemicalCorporation), Color Black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170,pre-Tex 35, U, V, 140U, Special Black 6, 5, 4A, 4, 250 (hereinbefore,product names, all manufactured by Degussa AG), Conduct Tex SC, Raven1255, 5750, 5250, 5000, 3500, 1255, 700 (hereinbefore, product names,all manufactured by Columbian Carbon Japan, Ltd.), Regal 400R, 330R,660R, Mogul L, Monarch 700, 800, 880, 900, 1000, 1100, 1300, 1400, andElf Tex 12 (hereinbefore, product names, all manufactured by CabotCorporation) are exemplified. The respective inorganic pigments may beused alone, or two or more kinds may be used in combination.

As organic pigments, which are not particularly limited, quinacridonepigments, quinacridonequinone pigments, dioxazine pigments,phthalocyanine pigments, anthrapyrimidine pigments, anthanthronepigments, indanthrone pigments, flavanthrone pigments, perylenepigments, diketopyrrolopyrrole pigments, perynone pigments,quinophthalone pigments, anthraquinone pigments, thioindigo pigments,benzimidazolone pigments, isoindoline pigments, azomethine pigments andazo pigments are exemplified. Specific examples of the organic pigmentinclude the following.

As the pigments used in a cyan ink, C. I. Pigment Blue 1, 2, 3, 15,15:1, 15:2, 15:3, 15:4, 15:6, 15:34, 16, 18, 22, 60, 65, 66, C. I. VatBlue 4, 60 and the like are exemplified. Among these, at least onebetween C. I. Pigment Blue 15:3 and 15:4 is preferable.

As the pigments used in a magenta ink, C. I. Pigment Red 1, 2, 3, 4, 5,6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32,37, 38, 40, 41, 42, 48 (Ca), 48 (Mn), 57 (Ca), 57:1, 88, 112, 114, 122,123, 144, 146, 149, 150, 166, 168, 170, 171, 175, 176, 177, 178, 179,184, 185, 187, 202, 209, 219, 224, 245, 254, 264, C. I. Pigment Violet19, 23, 32, 33, 36, 38, 43, 50 and the like are exemplified. Amongthese, one or more types selected from the group formed of C. I. PigmentRed 122, C. I. Pigment Red 202 and C. I. Pigment Violet 19 arepreferable.

As the pigments used in a yellow ink, C. I. Pigment Yellow 1, 2, 3, 4,5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74,75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120,124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 155, 167, 172, 180,185, 213 and the like are exemplified. Among these, one or more typesselected from the group formed of C. I. Pigment Yellow 74, 155 and 213are preferable. Moreover, as pigments used in inks having colors otherthan those described above, that is, inks such as a green ink or anorange ink, known pigments in the related art are exemplified.

As the white pigments, which are not particularly limited, whiteinorganic pigments such as titanium oxide, zinc oxide, zinc sulfide,antimony oxide and zirconium oxide are exemplified. The white organicpigments such as white hollow resin particles or polymer particles canalso be used instead of the white inorganic pigments.

As color indices (C. I.) of the white pigments, which are not limited,C. I. Pigment White 1 (basic lead carbonate), 4 (zinc oxide), 5 (mixtureof zinc sulfide and barium sulfate), 6 (titanium oxide), 6:1 (titaniumoxide containing other metal oxides), 7 (zinc sulfide), 18 (calciumcarbonate), 19 (clay), 20 (mica titanium), 21 (barium sulfate), 22(natural barium sulfate), 23 (gloss white), 24 (alumina white), 25(plaster), 26 (magnesium oxide and silicon oxide), 27 (silica) and 28(anhydrous calcium silicate) are exemplified.

Among the pigments, in the case where color ink and black ink includingat least one of color pigments and a carbon black pigment are used as apigment, a color image and a black image can be recorded on a lightcolor cloth such as a white cloth. Generally, when ink is adhered to acloth, the ink penetrates into the cloth and thus, the color developmentof the image is reduced. However, in the case of printing on a lightcolor cloth, for example, it is not necessary to apply a pretreatmentagent, which aggregates the ink components by reacting with the inkcomponents and as a result, inhibits penetration of the ink into thecloth, to the cloth before recording since the color development of theimage is comparatively slightly reduced even if the ink penetrates intothe cloth. In this case, since the heat press (heat press beforeadhesion of ink on cloth) for drying the pretreatment agent afterapplying the pretreatment agent is not performed, the fluff on thesurface of the cloth is particularly large, and therefore, the inventionis particularly useful.

2. Pigment Dispersion

The pigment may be present as a state in which the pigment is dispersedin the ink composition, that is, a pigment dispersion. Here, the pigmentdispersion in the specification includes a pigment dispersing liquid anda pigment slurry (low-viscosity aqueous dispersion).

D50 of dispersion of a white pigment is preferably in the range of 100nm to 600 nm and more preferably in the range of 200 nm to 500 nm. Whenthe D50 is 100 nm or greater, both the concealing property and thecoloring property tend to be improved. When the D50 is 1 μm or less,both the fixation of the ink and the discharging stability of the inktend to be improved.

As the pigment dispersions, which are not particularly limited, aself-dispersing type pigment and a polymer-dispersing type pigment areexemplified.

2-1. Self-Dispersing Type Pigment

The self-dispersing type pigment is a pigment which can be dispersed ordissolved in an aqueous medium without a dispersant. Here, “disperse ordissolve in an aqueous medium without a dispersant” refers to a statewhere the pigment is stably present in an aqueous medium due to ahydrophilic group of the surface thereof even if a dispersant fordispersing the pigment is not used. For this reason, an ink in whichfoaming resulting from deterioration of a defoaming property caused bythe dispersant practically does not occur, and which has excellentdischarging stability tends to be easily prepared. In addition, sincesignificant increase in the viscosity caused by the dispersant issufficiently suppressed, more pigment can be contained, print densitycan be sufficiently increased, and therefore handling is easy.

The hydrophilic group is preferably a hydrophilic group of one or moretypes selected from the group formed of —OM, —COOM, —CO—, —SO₃M, —SO₂M,—SO₂NH₂, —RSO₂M, —PO₃HM, —PO₃M₂, —SO₂NHCOR, —NH₃ and —NR₃.

Moreover, in these chemical formulas, M represents a hydrogen atom, analkali metal, ammonium, a phenyl group which may have a substituent oran organic ammonium, and R represents an alkyl group having 1 to 12carbon atoms or a naphthyl group which may have a substituent. Inaddition, M and R are selected independently of each other.

For example, the self-dispersing type pigment is manufactured by bonding(grafting) a hydrophilic group to the pigment surface by means ofperforming physical or chemical treatment to the pigment. As thephysical treatments, a vacuum plasma treatment and the like areexemplified. In addition, as the chemical treatment, a wet oxidationmethod in which the pigment surface is oxidized by an oxidant in waterand a method of bonding a carboxyl group via a phenyl group by means ofbonding p-aminobenzoic acid to the pigment surface and the like areexemplified.

2-2. Polymer-Dispersing Type Pigment

The polymer-dispersing type pigment is a pigment which is dispersed bypolymer dispersion. As the polymers used in the polymer-dispersing typepigment, which are not particularly limited, for example, the glasstransition temperature (T_(g)) of the dispersion polymer used in thedispersion of the pigment is preferably 55° C. or lower, and morepreferably 50° C. or lower. When the T_(g) is 55° C. or lower, there isa tendency that the fixation of the ink can be improved.

In addition, the weight average molecular weight of the polymersmeasured by gel permeation chromatography (GPC) is preferably in therange of 10,000 or greater to 200,000 or less. Accordingly, there is atendency that the storage stability of the ink is further improved.Here, the weight average molecular weight (Mw) in the specification canbe measured as the weight average molecular weight in terms ofpolystyrene by a gel permeation chromatography (GPC) of an L7100 systemmanufactured by Hitachi Ltd.

As the polymers, 70% by mass or greater of the components thereof ispreferably the polymer resulted from copolymerization of (meth)acrylateand (meth)acrylic acid. Thus, the fixation and glossiness of the inktend to be further improved. At least one of alkyl(meth)acrylate having1 to 24 carbon atoms and cyclic alkyl(meth)acrylate having 3 to 24carbon atoms is preferably polymerized from monomer components of 70% byweight or more. As specific examples of the monomer components, whichare not particularly limited, methyl(meth)acrylate, ethyl(meth)acrylate,propyl(meth)acrylate, n-butyl(meth)acrylate, isobutyl(meth)acrylate,pentyl(meth)acrylate, hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate,octyl(meth)acrylate, nonyl(meth)acrylate, decyl(meth)acrylate, t-butylcyclohexyl(meth)acrylate, lauryl(meth)acrylate, isobornyl(meth)acrylate,cetyl(meth)acrylate, stearyl(meth)acrylate, isostearyl(meth)acrylate,tetramethylpiperidyl(meth)acrylate, dicyclopentanyl(meth)acrylate,dicyclopentenyl(meth) acrylate, dicyclopentenyloxy(meth)acrylate andbehenyl(meth)acrylate are exemplified. In addition, as the other monomercomponents for polymerization, hydroxy(meth)acrylate,urethane(meth)acrylate and epoxy(meth)acrylate which have a hydroxylgroup such as hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylateand diethylene glycol(meth)acrylate can also be used.

2-3. Pigment Coated with Polymer

In addition, a pigment coated with the polymer among thepolymer-dispersing type pigments, that is, a micro-encapsulated pigmentis preferably used. Thus, the fixation, the glossiness and colorreproducibility of the ink tend to be improved.

The pigment coated with the polymer is obtained by a phase inversionemulsification method. In other words, the above-described polymer isdissolved in an organic solvent such as methanol, ethanol, isopropanol,n-butanol, acetone, methyl ethyl ketone, and dibutyl ether. The pigmentis added to the obtained solution, and then, kneading and dispersaltreatment are performed by adding water and a neutralizing agent. Bydoing this, the dispersion of an oil-in-water type is adjusted. Then,the pigment which is coated with the polymer can be obtained as a waterdispersion by removing the organic solvent from the obtained dispersion.For example, a ball mill, a roll mill, a bead mill, a high pressurehomogenizer and high-speed stirring type disperser and the like can beused in the kneading and the dispersal treatment.

As the neutralizing agents, ethylamine, tertiary amines such astrimethylamine, lithium hydroxide, sodium hydroxide, potassium hydroxideand ammonia and the like are preferable. The pH of the obtained aqueousdispersion is preferably in the range of 6 to 10.

The polymer which coats the pigment having the weight average molecularweight of about 10,000 to 150,000 measured by GPC is preferable from theviewpoint of stably dispersing the pigment.

Among the pigments which are coated with a polymer, a color pigmentwhich is coated with a polymer is preferable. The coloring property ofthe recorded material tends to be improved by using the color pigment.

3. Resin Dispersion

The ink composition used in the present embodiment preferably furtherincludes a resin dispersion. There is a tendency that the resindispersion can make the friction resistance and washing fastness of animage portion of the recorded material be more excellent since when theink is dried, resins, and a resin and a pigment are fused together,respectively, and the pigment is fixed on the recording medium. Theresin dispersion may be one in which a resin is dispersed in adispersion medium as fine particles. As the resin dispersions, adispersion, a suspension, an emulsion and the like can be used.Hereinafter, as an example of the resin dispersion, the emulsion (resinemulsion) will be described, but it is not limited to the resinemulsion, and the resin emulsion may be a resin dispersion. Among theresin emulsions, a urethane resin emulsion and an acrylic resin emulsionare preferable, and the urethane resin emulsion is more preferable.Thus, since the fixation of the ink becomes excellent, both the frictionresistance and the washing fastness of the recorded material tend to beimproved.

In the case where the resin emulsion is included in the ink composition,the resin emulsion sufficiently fixes the ink composition on a recordingmedium by forming a resin film on the recording medium and thus, thefriction resistance of the recorded material becomes excellent. For thisreason, the resin emulsion is preferably a thermoplastic resin. Inparticular, desired physical properties of the film are easily obtainedsince the urethane resin emulsion has a high flexibility of design.

The urethane resin emulsion is an emulsion which has a urethane bond ina molecule. Further, as the urethane resin emulsions, a polyether typeurethane resin including an ether bond in a main chain, a polyester typeurethane resin including an ester bond in the main chain, and apolycarbonate type urethane resin including a carbonate bond in the mainchain in addition to the urethane bond can also be used.

Hereinafter, preferred physical properties of the resin emulsion will bedescribed. In general, in the temperature range (the range of 15° C. to35° C.) in which the ink jet recording is performed, the resin emulsionpreferably has film-forming property. For this reason, the T_(g) ispreferably −10° C. or lower, and more preferably −15° C. or lower. Inthe case where the T_(g) of the resin emulsion is in the above range,the fixation of the ink which is adhered to the recorded materialbecomes more excellent, and therefore, the friction resistance of therecorded material tends to become excellent. Moreover, the lower limitof the T_(g), which is not particularly limited, may be −50° C. orhigher.

Furthermore, the acid value of the resin emulsion is preferably in therange of 10 mg KOH/g to 100 mg KOH/g and more preferably in the range of15 mg KOH/g to 50 mg KOH/g. When the acid value is 100 mg KOH/g or less,there is a tendency that the washing fastness of the recorded materialcan be excellently maintained. In addition, when the acid value is 10 mgKOH/g or higher, the storage stability of the ink, the coloring propertyand the fixation of the ink on a recording medium tend to becomeexcellent. Moreover, the acid value in the specification is measuredusing AT610 manufactured by Kyoto Electronics Manufacturing Co., Ltd.,and the values calculated by applying numeric values to the followingformula are adopted.

Acid value (mg/g)=(EP1−BL1)×FA1×C1×K1/SIZE

In the formula, EP1 represents a titration amount (mL), BL1 represents ablank value (0.0 mL), FA1 represents a factor of titrant (1.00), C1represents a concentration conversion value (5.611 mg/mL) (amountcorresponding to 1 mL KOH having a concentration of 0.1 mol/L), K1represents a coefficient (1), and SIZE represents the amount of a sample(g).

In addition, the resin emulsion preferably has the elongation at a breakin the range of 500% to 1,200%, and preferably has the elastic modulusin the range of 20 MPa to 400 MPa. When the elongation at the break andthe elastic modulus are in the above range, even in the case of printingon a cloth which easily expands or contracts among cloths, there is atendency that the cracking and the breaking of an image, that is, of anink layer can be suppressed, and the friction resistance and the washingfastness of the recorded material tend to become excellent.

Here, after preparing a film having a thickness of about 60 μm, theelongation at the break in the specification can be measured under theconditions of a tensile test gauge length of 20 mm and a tensile speedof 100 mm/min. In addition, in a measurement of the elastic modulus inthe specification, after preparing a film having a thickness of about 60μm and forming a dumbbell specimen having a parallel portion width of 10mm and a length of 40 mm, a tensile elasticity can be measured based onJIS K7161:1994.

Moreover, to be more specific, the JIS K7161:1994 corresponds to theinternational standard ISO 527-1:1993, the title thereof is a testmethod for plastic-tensile property, and the standard defines thegeneral principles for measuring the tensile property of a plastic and aplastic composite under the predetermined conditions.

D50 of the resin emulsion is preferably in the range of 30 nm to 300 nm,and more preferably in the range of 80 nm to 300 nm. When D50 is in theabove range, the resin emulsion particles in the ink composition can beuniformly dispersed. The lower limit value of D50 is more preferably 100nm. When the D50 is in the above range, the friction resistance of therecorded material tends to become more excellent.

From the viewpoint of the physical properties of the resin emulsiondescribed above, as commercially available products of the urethaneresin emulsion, which are not particularly limited, Suncure 2710(product name, manufactured by Lubrizol Corp.), Permarin UA-150 (productname, manufactured by Sanyo Chemical Industries, Ltd.), Superflex 460,470, 610, 700 (hereinbefore, product names, all manufactured by Dai-ichiKogyo Seiyaku Co., Ltd.), NeoRez R-9660, R-9637, R-940 (hereinbefore,product names, all manufactured by Kusumoto Chemicals, Ltd.), AdekaBontighter HUX-380, 290K (hereinbefore, product names, all manufacturedby Adeka Co., Ltd.), Takelac (registered trademark) W-605, W-635,WS-6021 (hereinbefore, product names, all manufactured by MitsuiChemicals, Inc.), Polyether (product name, manufactured by TaiseiFinechemical Co., Ltd., T_(g)=20° C.) are preferably exemplified.

The urethane-based resin may be used alone or two or more kinds may beused in combination.

In addition, the ink composition used in the embodiment preferablyincludes a resin emulsion other than the urethane resin emulsion. Amongthe resin emulsions, an anionic resin emulsion is preferable since theanionic resin emulsion can effectively prevent a resin from aggregating.As the anionic resin emulsions, which are not particularly limited, ahomopolymer or a copolymer of (meth)acrylic acid, (meth)acrylic acidester, acrylonitrile, cyanoacrylate, acrylamide, olefin, styrene, vinylacetate, vinyl chloride, vinyl alcohol, vinyl ether, vinylpyrrolidone,vinyl pyridine, vinylcarbazole, vinyl imidazole and vinylidene chloride,a fluororesin and a natural resin are exemplified. Among these, at leastone of a (meth)acrylic resin and a styrene-(meth)acrylic acid copolymerresin is preferable, at least one of an acrylic resin and astyrene-acrylic acid copolymer resin is more preferable and astyrene-acrylic acid copolymer resin is further more preferable.Moreover, the copolymers may be any form of a random copolymer, a blockcopolymer, an alternating copolymer and a graft copolymer.

As resin emulsions other than the urethane resin emulsion, thoseobtained by known materials and the preparing method may be also used,and commercially available products may be also used. As thecommercially available products, which are not particularly limited,Mowinyl 966A (product name, manufactured by Nippon Synthetic ChemicalsIndustry Co., Ltd, acrylic resin emulsion), Microgel E-1002, MicrogelE-5002 (hereinbefore, product names, both manufactured by Nippon PaintCo., Ltd.), Voncoat 4001, Voncoat 5454 (hereinbefore, product names,both manufactured by DIC Corp.), SAE1014 (product name, manufactured byNippon Zeon Corp.), Saibinol SK-200 (product name, manufactured by(SAIDEN CHEMICAL INDUSTRY CO., LTD.), JONCRYL 7100, JONCRYL 390, JONCRYL711, JONCRYL 511, JONCRYL 7001, JONCRYL 632, JONCRYL 741, JONCRYL 450,JONCRYL 840, JONCRYL 74J, JONCRYL HRC-1645J, JONCRYL 734, JONCRYL 852,JONCRYL 7600, JONCRYL 775, JONCRYL 537J, JONCRYL 1535, JONCRYLPDX-7630A, JONCRYL 352J, JONCRYL 352D, JONCRYL PDX-7145, JONCRYL 538J,JONCRYL 7640, JONCRYL 7641, JONCRYL 631, JONCRYL 790, JONCRYL 780,JONCRYL 7610 (hereinbefore, product names, all manufactured by BASFCorp.), and NK binder R-5HN (product name, manufactured by Shin-NakamuraChemical Co., acrylic resin emulsion, 44% solid content) areexemplified. Among these, Mowinyl 966A which is an acrylic resinemulsion is preferable since Mowinyl 966A sufficiently satisfiesdesirable physical properties of the resin emulsion described above.

Resin emulsions other than the urethane resin emulsion may be used aloneor two or more kinds may be used in combination.

Here, the content of the resin in the resin emulsion will be described.The lower limit of the content of the resin in the resin emulsion ispreferably 3% by mass or greater, more preferably 4% by mass or greater,and still more preferably 5% by mass or greater with respect to thetotal mass (100% by mass) of a ink composition. The upper limit ispreferably 15% by mass or less, more preferably 13% by mass or less, andstill more preferably 10% by mass or less. When the content is in theabove range, the friction resistance and the washing fastness of therecorded material tend to become excellent, and there are tendenciesthat the long-term storage stability of the ink composition isexcellent, and particularly, the viscosity of the ink composition can belowered.

4. Cyclic Amide Compound

The ink composition used in the embodiment preferably further includes acyclic amide compound. The cyclic amide compound has a function forimproving the solubility of a lactic acid ester compound in water.Therefore, since when the ink composition also includes a cyclic amidecompound together with a lactic acid ester compound, a solubility of aurethane resin (emulsion) increases, and the storage stability,particularly, the storage stability at high temperatures tends to becomemore excellent.

In addition, since the cyclic amide compound also has the moistureretaining function, the cyclic amide compound can prevent aggregationand solidification caused by evaporation of water in a urethane resin(emulsion), other resins (polymer) and a pigment during a storage of anink. Thus, clogging near the nozzle of a head during an ink jetrecording can be prevented, and the discharging stability of the inkcomposition tends to become excellent.

As specific examples of the cyclic amide compound, which are notparticularly limited, 2-pyrrolidone, N-methyl-2-pyrrolidone andN-ethyl-2-pyrrolidone are exemplified. Among these, 2-pyrrolidone ispreferable since solubility with respect to a resin (polymer) isstrengthened further and the storage stability, particularly, thestorage stability at high temperature becomes even more excellent.

The cyclic amide compound may be used alone or two or more kinds may beused in combination.

The content of the cyclic amide compound is preferably in the range of0.5% by mass to 5% by mass, and more preferably in the range of 1% bymass to 3% by mass with respect to the total mass (100% by mass) of anink composition. When the content is in the above range, the frictionresistance and the washing fastness of the recorded material caused bythe long-term storage stability of an ink, the discharging stability ofan ink and the excellent fixation of an ink become more excellent.

5. Water-Soluble Solvent

The ink composition used in the embodiment can include a water-solublesolvent and preferably includes water. As the aqueous solvents, waterand water-soluble organic solvents are exemplified. As water, which isnot particularly limited, pure water such as ion exchange water,ultrafiltration water, reverse osmosis water and distilled water orultrapure water can be used. The content of the water, which is notparticularly limited, may be suitably determined as necessary, and maybe preferably in the range of 20% by mass to 80% by mass with respect tothe total mass (100% by mass) of an ink composition in order to adjustthe viscosity of the ink composition to be in a suitable range.

Moreover, to avoid duplication, various additives (components) whichwill be described below do not include the cyclic amide compound.

6. Penetrating Agent

Since the ink composition used in the embodiment further promotes theaqueous solvent which is a component thereof penetrating into arecording medium, the ink composition may further contain a penetratingagent. There is a tendency that the recorded material in which bleedingof an image is small can be obtained by fast penetration of the aqueoussolvent into a cloth.

As the penetrating agents, alkyl ethers (glycol ethers) of polyhydricalcohols and 1,2-alkyldiols are preferably exemplified. As the glycolethers, which are not limited to the following, ethylene glycolmonomethyl ether, ethylene glycol monoethyl ether, ethylene glycolmonopropyl ether, ethylene glycol monobutyl ether, ethylene glycolmonomethyl ether acetate, diethylene glycol monomethyl ether, diethyleneglycol monoethyl ether, diethylene glycol monopropyl ether, diethyleneglycol monobutyl ether, diethylene glycol mono-t-butyl ether,triethylene glycol monobutyl ether, 1-methyl-1-methoxy butanol,propylene glycol monomethyl ether, propylene glycol monoethyl ether,propylene glycol monopropyl ether, propylene glycol monobutyl ether,dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether,dipropylene glycol monopropyl ether, propylene glycol monobutyl etherand dipropylene glycol monobutyl ether are exemplified. In addition, asthe 1,2-alkyldiols, which are not particularly limited, 1,2-pentanedioland 1,2-hexanediol are exemplified. Diols having a straight-chainhydrocarbon such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol,1,6-hexanediol, 1,7-heptanediol and 1,8-octanediol in addition to thesecan also be exemplified.

The penetrating agent may be used alone or two or more kinds may be usedin combination.

The content of the penetrating agent is preferably in the range of 0.1%by mass to 20% by mass, and more preferably in the range of 0.5% by massto 10% by mass with respect to the total mass (100% by mass) of an inkcomposition. When the content is 0.1% by mass or more, there is atendency that the penetration into the cloth of the ink compositionincreases. In contrast, when the content is 20% by mass or less, thereis a tendency that generation of bleeding in the image can be prevented,and the viscosity of the ink composition can be made not to be high.

7. Moisturizing Agent

The ink composition used in the embodiment may further include amoisturizing agent (wetting agent). The moisturizing agent can be usedwithout being particularly limited as long as it is generally used inthe ink jet ink. A moisturizing agent having a high boiling point ofwhich the boiling point is preferably 180° C. or higher, and morepreferably 200° C. or higher may be used. In the case where the boilingpoint is in the above range, excellent water holding property andwetting property can be applied to the ink composition.

As specific examples of the moisturizing agent having a high boilingpoint, which are not particularly limited, ethylene glycol, propyleneglycol, diethylene glycol, triethylene glycol, pentamethylene glycol,trimethylene glycol, 2-butene-1,4-diol, 2-ethyl-1,3-hexanediol,2-methyl-2,4-pentanediol, tripropylene glycol, polyethylene glycolhaving a number average molecular weight of 2000 or less, 1,3-propyleneglycol, isopropylene glycol, isobutylene glycol, glycerin,meso-erythritol and pentaerythritol are exemplified.

The moisturizing agent may be used alone or two or more kinds may beused in combination. When the ink composition includes the moisturizingagent having a high boiling point, there is a tendency that fluidity andredispersibility can be maintained for a long period of time even if theink composition is left in a state where the pigment ink is exposed toair in an open state.

Furthermore, in such an ink composition, since the clogging of thenozzle is unlikely to occur while printing is performed using the inkjet recording apparatus or at the time of being restarted after aninterruption, the discharging stability of the ink composition tends tobecome excellent. The content of the moisturizing agent is notparticularly limited and may be suitably determined as necessary.

Moreover, as described above, in the case where the ink compositionincludes a cyclic amide compound, since the cyclic amide compound has amoisture retaining function, the cyclic amide compound can be used asthe moisturizing agent.

8. Surfactant

The ink composition used in the embodiment may include a surfactant. Asthe surfactants, at least one of an acetylene glycol-based surfactant,an acetylene alcohol-based surfactant and a polysiloxane-basedsurfactant is preferable. When the ink composition includes thesesurfactants, the drying property of the ink composition adhering to acloth becomes more excellent, and high-speed printing tends to becomepossible.

Among these, polysiloxane-based surfactants are more preferable sincethe solubility in the ink is increased and foreign matter is less likelyto be generated.

As the acetylene glycol-based surfactants and the acetylenealcohol-based surfactant, which are not particularly limited, one ormore kinds selected from alkylene oxide adducts of2,4,7,9-tetramethyl-5-decyne-4,7-diol and alkylene oxide adducts of2,4,7,9-tetramethyl-5-decyne-4,7-diol, and 2,4-dimethyl-5-decyne-4-oland 2,4-dimethyl-5-decyne-4-ol are preferable. These can be available ascommercially available products such as E series (product name,manufactured by Air Products Japan, Inc.) of Olfine 104 series andOlfine E1010, Surfynol 465 and Surfynol 61 (product names, manufacturedby Nissin Chemical Industry Co., Ltd.).

In addition, as the polysiloxane-based surfactants, BYK-347 and BYK-348(product names, manufactured by BYK Japan KK) are exemplified.

The content of the surfactant is preferably in the range of 0.1% by massto 3% by mass with respect to the total mass (100% by mass) of the inkcomposition.

9. Other Components

In the ink composition used in the embodiment, various additives such asa moisturizing agent, a solubilizer, a seepage control agent, aviscosity modifier, a pH adjusting agent, an antioxidant, apreservative, an antifungal agent, a corrosion inhibitor and a chelatingagent for capturing metal ions which affect dispersion can be suitablyadded in order to maintain excellent storage stability thereof andexcellent discharge stability from the head, to improve anti-cloggingperformance or to prevent deterioration of the ink.

4. Ink Jet Recording Apparatus

The ink jet recording apparatus of the embodiment is not particularlylimited as long as recording is performed by the ink jet recordingmethod for printing pigment, and may have the same configuration asthose in the related art as long as it has the configuration describedabove.

EXAMPLES

Hereinafter, the invention will be more specifically described usingExamples and Comparative Examples. The invention is not limited to theseExamples.

1. Material for Ink Composition

The main material for the ink composition used in the following Examplesand Comparative Examples are as follows.

Coloring Material

Cyan pigment (C. I. Pigment Blue 15:3 manufactured by Clariant Co.,Ltd.)

Cyan pigment (C. I. Disperse Blue 60 manufactured by DyStar ColoursDistribution GmbH)

Resin Emulsion

Takelac WS-6021 (product name, manufactured by Mitsui ChemicalsPolyurethanes, Inc., 30% solid content, urethane resin emulsion)

Dispersant

DEMOL NL (product name, manufactured by Kao Chemical Co., 41% solidcontent)

Organic Solvent

Glycerin

Triethylene glycol

Triethylene glycol monobutyl ether Silicone-based surfactant

BYK-348 (product name, manufactured by BYK Co., Ltd.)

2. Preparation of Ink Composition

By mixing according to the composition (% by mass) shown in Table 1 andsufficiently stirring, ink compositions 1 and 3 were obtained.

TABLE 1 Ink No. 1 2 3 Cyan pigment (C.I. Pigment Blue 15:3 5.00 3.00 —manufactured by Clariant Co., Ltd.) Cyan pigment (C.I. Disperse Blue 60— — 5   manufactured by DyStar Colours Distribution GmbH) TakelacWS-6021 (as solid content) 6.00 3.60 — Dispersion DEMOL NL (41% solid1.20 0.72 — content) Glycerin 8.00 8.00 8.00 Triethylene glycol 3.003.00 3.00 Triethylene glycol monobutyl ether 1.00 1.00 1.00 BYK-348 0.300.30 0.30 Ion exchange water balance balance balance About About 7% Dyeink 11% solid solid content content

3. Cloth

As the cloth of 100% cotton, texture of T-shirts (white, 5 ounces)manufactured by HANES Inc. was used. In addition, as the cloth ofcotton-polyester blended fibers, texture of T-shirts (white)manufactured by HANES Inc. and blended fibers (75% cotton and 25%polyester) were used. Furthermore, as cloth of 100% polyester, texture(100% polyester, white, 4.1 ounces) of T-shirts made of polyester wasused.

4. Ink Jet Recording Apparatus

A printer SC-S30650 (manufactured by Seiko Epson Corporation) which wasremodeled was used (hereinafter, referred to as “remodeled SC-S30650printer”). The remodeled portions are as follows. A dischargingmechanism was provided, and a recording medium made of cloth was made tobe supportable and transportable.

The head at the time of printing having a nozzle density of one nozzlearray of 360 dpi was used. In addition, in the discharging mechanism,using the driving pulses as shown in FIG. 2, the drive pulse was appliedto a piezoelectric element provided to each nozzle and thus, ink wasdischarged from the nozzle. One recording cycle (frequency) was set to7.2 kHz, the discharging frequency at the time of applying three drivingpulses PW1 to PW3 of one recording cycle to the piezoelectric elementwas set to 21.6 kHz (average). In addition, the carriage speed wasadjusted to set the dot formation density in the main scanning directionof each array. Furthermore, the gradients θ12, θ22 and θ32 of thecharging elements P13, P23 and P33 of the driving pulses PW1, PW2 andPW3 were changed to adjust the discharging speed. By adjusting thepotential difference of the charging elements P13, P23 and P33, thedischarging amount of the ink droplet can be adjusted.

The distance from the nozzle opening to a cloth was adjusted by raisingor lowering the position of the recording medium support portion. Inaddition, the passage time during which ink droplets passed through thedistance in the range of 0.5 mm to 1.0 mm in the direction of the clothfrom the nozzle opening was measured by capturing an image with a highspeed camera from a side of the nozzle surface, and the averagedischarging speed V was calculated from the measured values.

5. Ink Jet Recording Method (Examples 1 to 10, Comparative Examples 1 to8, and Reference Examples 1 to 2)

Using the remodeled SC-S30650 printer, any one of the ink compositions 1to 3 which was prepared as described above was discharged under theprinting condition of each example shown in Table 2 by the ink jetrecording method, and 20×20 cm patterns adhered to the cloth which wasset to the A4 size.

The cloth onto which the ink composition adhered was heat-treated at160° C. for 1 minute using a heat press machine to fix the inkcomposition on the cloth. In addition, in Comparative Example 7, thecloth was left in an oven at 160° C. for 5 minutes to dry, without usingthe heat press. In this manner, the recorded material in which an imagewas formed (ink was printed) on the cloth was prepared. At this time,the following evaluation was performed with respect to the obtainedrecorded material.

6. Evaluation

Adhered Amount of the Ink (mg/inch²)

The adhered amount of the ink was obtained from the dot formationdensity by the following formula (except for Example 8 and ComparativeExample 6)

Adhered amount of the ink (mg/inch²)=amount of the ink of the inkdroplet (ng)×dot formation density in the horizontal direction (dpi)×dotformation density in the vertical direction (dpi)×2×10⁻⁶

Contamination of Cloth

A pattern prepared as described above was visually observed. Thecontamination of cloth was evaluated according to the followingevaluation criteria.

Evaluation Criteria

B: Contamination considered to be transported to the base portion ofcloth from the collapsed fluff was not observed.C: Contamination considered to be transported to the base portion ofcloth from the collapsed fluff was slightly observed.D: Contamination considered to be transported to the base portion ofcloth from the collapsed fluff was greatly observed.

Concealing Property of Image

A pattern of a sample which was prepared in the evaluation of thecontamination of a cloth was visually observed. The concealing propertyof an image was evaluated according to the following evaluationcriteria.

Evaluation Criteria

B: When observed from the top of a pattern, white texture was not seenthrough.C: When observed from the top of a pattern, white texture was slightlyseen through.D: When observed from the top of a pattern, white texture was clearlyseen through.

Printing Speed

The necessary time for printing one sheet in other Examples comparedwith in Example 1 was measured. The printing speed was evaluatedaccording to the following evaluation criteria.

Evaluation Criteria

O: Fewer than two timesX: Two times or more

Drying Speed

After printing a pattern according to the same method as in theevaluation of the contamination of a cloth, a solid image (ink dropletof 5 ng, dot density of 2880×1440 dpi) of 10×10 cm was further printedinside the pattern by using magenta ink without fixing by a heat press.The time interval between cyan ink printing and magenta ink printing wasset to be in the range of 30 seconds to 1 minute. The bleeding in aboundary of the cyan pattern and magenta pattern after printing wasvisually observed. Moreover, the drying speed was evaluated according tothe following evaluation criteria. As the magenta ink, an ink in whichPigment Red 122 (manufactured by Clariant Co., Ltd.) of 5% by massinstead of cyan pigment in the ink composition 1 was included wasadjusted to be used.

Evaluation Criteria

B: no bleedingC: slight bleedingD: bleeding

TABLE 2 Example 1 Example 2 Example 3 Example 4 Example 5 Ink No. 1 1 12 1 Average discharging speed m/s 5 10 12 5 5 Amount of ink of inkdroplet ng 5 5 3 5 9 Distance between nozzle surface 2 2 2 4 2 and clothmm Heat press 160° C. × 1 minute Performed Performed Performed PerformedPerformed Type of cloth 100% cotton 100% cotton 100% cotton 100% cotton100% cotton Dot formation density dpi 2880 × 1440 2880 × 1440 2880 ×1440 2880 × 1440 1440 × 1440 Adhered amount of the ink mg/inch² 20.720.7 12.4 20.7 18.7 Contamination of cloth B B B B B Concealing propertyof image B B C C B Printing speed B B B B B Drying speed B B B B BExample 6 Example 7 Example 8 Example 9 Example 10 Ink No. 1 1 1 1 1Average discharging speed m/s 5 5 5 5 5 Amount of ink of ink droplet ng5 5 5 5 5 Distance between nozzle surface 4 1 1 2 2 and cloth mm Heatpress 160° C. × 1 minute Performed Performed Performed Not performedPerformed Type of cloth 100% cotton 100% cotton 100% cotton 100% cotton100% polyester Dot formation density dpi 2880 × 1440 2880 × 1440 2880 ×1440 2880 × 1440 2880 × 1440 Adhered amount of the ink mg/inch² 20.720.7 70 20.7 20.7 Contamination of cloth C B B B B Concealing propertyof image B B B B B Printing speed B B D B B Drying speed B B C B BComparative Comparative Comparative Comparative Comparative Example 1Example 2 Example 3 Example 4 Example 5 Ink No. 1 2 1 1 1 Averagedischarging speed m/s 3 3 5 3 5 Amount of ink of ink droplet ng 5 5 1313 13 Distance between nozzle surface 2 2 2 2 2 and cloth mm Heat press160° C. × 1 minute Performed Performed Performed Performed PerformedType of cloth 100% cotton 100% cotton 100% cotton 100% cotton 100%cotton Dot formation density dpi 2880 × 1440 2880 × 1440 2160 × 720 2160× 720 2160 × 360 Adhered amount of the ink mg/inch² 20.7 20.7 20.2 20.210.1 Contamination of cloth D D B B B Concealing property of image B C BB D Printing speed B B B B B Drying speed B B D D B ComparativeComparative Comparative Reference Reference Example 6 Example 7 Example8 Example 1 Example 2 Ink No. 1 1 1 3 3 Average discharging speed m/s 33 3 5 3 Amount of ink of ink droplet ng 5 5 5 5 5 Distance betweennozzle surface 2 2 1 2 2 and cloth mm Heat press 160° C. × 1 minutePerformed Performed Performed Performed Performed Type of cloth 100%cotton Cotton- 100% cotton 100% cotton 100% cotton polyester blendedfibers Dot formation density dpi 2880 × 1440 2880 × 1440 2880 × 14402880 × 1440 2880 × 1440 Adhered amount of the ink mg/inch² 103.5 20.720.7 20.7 20.7 Contamination of cloth B D D B B Concealing property ofimage B B B C C Printing speed D B B B B Drying speed D B B B B

From the results above, it was found that in Examples 1 to 10 using theink jet recording method for printing a pigment which satisfiesrequirements of the invention, the contamination of a cloth is unlikelyto occur, the concealing property of an image is excellent, and thedrying speed is also fast.

Among Examples, in Example 6 in which the distance between the nozzlesurface and the cloth was set to 4 mm, the contamination of a cloth wasslightly inferior, and it is presumably because the flying distance ofthe ink droplets was increased, and thus, the number of ink dropletswhich cannot land on the base portion of the cloth due to air resistancewas increased. In contrast, in Example 4, the distance between thenozzle surface and the cloth was the same as in Example 6. However, thecontamination of the cloth was the same as in Example 1, and theconcealing property of an image is slightly inferior. This is presumablybecause, since the ink No. 2 used in Example 4 has a lower solid contentof the ink than in the ink No. 1, the ink components which become thecontamination of a cloth were small.

Example 8 and Comparative Example 6 are examples in which the adheredamount of the ink was increased by increasing the number of passes, andsince the adhered amount of the ink was increased by forming dotsseveral times at the same position on the cloth, the apparent dotformation density becomes the same as in Example 1.

In Examples 7 and 8 and Comparative Example 8, the distance between thenozzle surface and the cloth was set to 1 mm, and among these, inExample 8, since the adhered amount of the ink was large, the clothexpanded due to the adhesion of the ink during printing, and contactwith the head occurred. However, since the contamination of the clothdue to collapse of the fluff did not occur, it is excellent in theevaluation of the contamination of the cloth.

Example 10 is an example in which 100% polyester was used as the type ofcloth. It was thought that since the fluff of the cloth surface issmall, the contamination of the cloth due to collapse of the fluff doesnot occur. However, Examples 1 to 9 were more excellent than Example 10in which the cloth was polyester in terms of texture. In contrast, inComparative Example 7 in which cloth of cotton-polyester blended fiberswas used as the cloth, the contamination of the cloth occurred.

The ink composition 3 including dye needs a chemical treatment or avapor heat treatment to fix the dye. However, in Reference Examples 1and 2, discoloration was performed by washing since only a heat presswas performed as a treatment after printing. In addition, it was foundthat the concealing property is inferior.

On the other hand, it was found that in Comparative Examples 1, 2, 7 and8 in which the average discharging speed was low, the contamination ofthe cloth occurred. In addition, it was found that in ComparativeExample 4 in which the average discharging speed was low, and the amountof the ink of the ink droplets was large, the drying speed was low, andin Comparative Example 6 in which the adhered amount of the ink waslarge, the printing speed and the drying speed were low. Furthermore, itwas found that in Comparative Example 3 in which the amount of the inkof the ink droplets was large, the drying speed was low, and inComparative Example 5 in which the amount of the ink of the ink dropletswas large and the dot formation density was low, the concealing propertyof an image was poor.

In Example 9, the contamination of the cloth was excellent. However, itwas observed that fluff was erect on the surface of the cloth in theportion at which an image of recorded material was recorded, and alittle color was attached to fuzz.

The ink jet recording method of the invention is industrially applicableas a method which records an ink composition on a cloth.

The entire disclosure of Japanese Patent Application No.: 2013-036776,filed Feb. 27, 2013 is expressly incorporated by reference herein.

What is claimed is:
 1. An ink jet recording method for printing apigment, wherein a pigment printing ink composition including at leastpigment as a colorant is discharged from a nozzle opening as an inkdroplet having an amount of an ink of 9 ng or less with an averagedischarging speed V of 5 m/s or greater at a distance in the range of0.5 mm to 1.0 mm in the direction from the nozzle opening to cloth, andthe pigment printing ink composition is adhered to the cloth.
 2. The inkjet recording method for printing a pigment according to claim 1,wherein the distance between the nozzle opening and the cloth is in therange of 2.0 mm to 5.0 mm.
 3. The ink jet recording method for printinga pigment according to claim 1, wherein the amount of the ink of the inkdroplet is 5.9 ng, and the average discharging speed V is in the rangeof 5 m/s to 10 m/s.
 4. The ink jet recording method for printing apigment according to claim 1, wherein the solid content of the pigmentprinting ink composition is 8% by mass or greater.
 5. The ink jetrecording method for printing a pigment according to claim 1, whereinthe pigment printing ink composition includes a pigment, and a resindispersion.
 6. The ink jet recording method for printing a pigmentaccording to claim 1, wherein the cloth includes cotton or a cottonblend.
 7. The ink jet recording method for printing a pigment accordingto claim 1, wherein after the pigment printing ink composition isadhered to the cloth, the cloth to which the pigment printing inkcomposition is adhered is heat-treated by a heat press.
 8. The ink jetrecording method for printing a pigment according to claim 7, wherein aheating temperature is 150° C. or higher in the heat treatment.
 9. Theink jet recording method for printing a pigment according to claim 1,wherein the amount of the pigment printing ink composition adhering tothe cloth is in the range of 10 mg/inch² to 70 mg/inch².
 10. The ink jetrecording method for printing a pigment according to claim 1, wherein adot formation density of the pigment printing ink composition on thecloth is 720 dpi or greater×720 dpi or greater.
 11. The ink jetrecording method for printing a pigment according to claim 1, whereinthe pigment printing ink composition is any one of a color ink includingat least color pigment as a pigment and a black ink including at leastcarbon black pigment as a pigment.
 12. An ink jet recording apparatus,wherein recording is performed by the ink jet recording method forprinting a pigment according to claim
 1. 13. An ink jet recordingapparatus, wherein recording is performed by the ink jet recordingmethod for printing a pigment according to claim
 2. 14. An ink jetrecording apparatus, wherein recording is performed by the ink jetrecording method for printing a pigment according to claim
 3. 15. An inkjet recording apparatus, wherein recording is performed by the ink jetrecording method for printing a pigment according to claim
 4. 16. An inkjet recording apparatus, wherein recording is performed by the ink jetrecording method for printing a pigment according to claim
 5. 17. An inkjet recording apparatus, wherein recording is performed by the ink jetrecording method for printing a pigment according to claim
 6. 18. An inkjet recording apparatus, wherein recording is performed by the ink jetrecording method for printing a pigment according to claim
 7. 19. An inkjet recording apparatus, wherein recording is performed by the ink jetrecording method for printing a pigment according to claim
 8. 20. An inkjet recording apparatus, wherein recording is performed by the ink jetrecording method for printing a pigment according to claim 9.